When I process a new RAW wide-angle image initially with DxO (Version 8, in my case), then process the resulting DxO image with CornerFix, not only do I accomplish my desired lightening of the corners, but there appears to me a color shift as well in the whole image, a general lightening of all color tones. I suppose this result should not surprise me, but I would welcome an explanation of what is happening and how detrimental this use of CornerFix to a DxO processed image is. CornerFix only works with DNG files, so I suppose I could convert my RAW images first to DNG, then apply CornerFix, and only then process with DxO. What think?

You can prevent CornerFix from making any changes to color by setting the chroma slider to zero; in that case CornerFix will correct only for luminance shifts.

Sandy

Sandy: The CornerFix instructions regarding chroma and luminance settings are a bit confusing to me. As I do want to retain some minor vignetting, I've set my luminance to 0.5 but retained the chroma at the default setting of 1.0. But the instructions seems to state that the luminance setting alters all colors. In any case, I believe I'll have a go at Walter's suggestion that I try the vignetting control in DxO itself. Many thanks. Jim

Sandy: The CornerFix instructions regarding chroma and luminance settings are a bit confusing to me. As I do want to retain some minor vignetting, I've set my luminance to 0.5 but retained the chroma at the default setting of 1.0. But the instructions seems to state that the luminance setting alters all colors. In any case, I believe I'll have a go at Walter's suggestion that I try the vignetting control in DxO itself. Many thanks. Jim

Jim,

Chroma at zero will zero out the color adjustment, but keep the luminance adjustment.

Chroma at zero will zero out the color adjustment, but keep the luminance adjustment.

Sandy

Sandy: Thanks for the clarification. Now, I'll have to also see whether I'll be able to integrate CornerFix with Sigma Photo Pro RAW processing when my new Sigma SD15 camera arrives, as I'm certain that DxO will be of no use with that camera's proprietary Foveon format. Thanks again. Jim

You won't be able to "integrate" CornerFix with Sigma SPP. I've done some tests, and since CornerFix only works with DNG files, you need to export 16 bit tiffs from SPP, import them into Lightroom and re-export as DNG (these files will still essentially be tiff files, not RAW DNG's). You can then open up the new DNG's in CornerFix. This is not the best workflow. I'm currently testing profiles, made from tiffs with Adobe Lens Profile Creator, these profiles can be accessed from within LR when you do further processing after SPP. My Sigma files are from the DP2 Merrill. It's best to do your own tests and see which flow works for the best.

You won't be able to "integrate" CornerFix with Sigma SPP. I've done some tests, and since CornerFix only works with DNG files, you need to export 16 bit tiffs from SPP, import them into Lightroom and re-export as DNG (these files will still essentially be tiff files, not RAW DNG's). You can then open up the new DNG's in CornerFix. This is not the best workflow. I'm currently testing profiles, made from tiffs with Adobe Lens Profile Creator, these profiles can be accessed from within LR when you do further processing after SPP. My Sigma files are from the DP2 Merrill. It's best to do your own tests and see which flow works for the best.

Pete: Sigma SSP is a real "piece of work" as they say, as has been already well pointed out in this forum. Good luck in your tests. Please keep us informed. Thanks for you help. Jim

Compared to LR, Capture 1 etc, SPP shows it's weakness but I find it quite usable, my main gripe is that it forces you to keep tiff "originals" as well as the initial X3F's, and that apps such as CornerFix, which is designed around the open DNG standard become harder to incorporate into a workflow. That said I have found that CF does work well at reducing the magenta/green casts that are obvious in some Merrill files (but by no means all). I did my initial Adobe Lens Profile (for the DP2M 30mm lens) in a rush, and although these work well too, they did indicate that there was some distortion in the lens, which I thought was practically distortion free. This leads me to be suspicious of the profile I quickly created, so I need to go through the process again, in a more structured way, in order to make sure the profile is good. If I can get to the bottom of this I will report back.